Multi-zone EC windows

ABSTRACT

Thin-film devices, for example, multi-zone electrochromic windows, and methods of manufacturing are described. In certain cases, a multi-zone electrochromic window comprises a monolithic EC device on a transparent substrate and two or more tinting zones, wherein the tinting zones are configured for independent operation.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a national stage application under 35 U.S.C. § 371to International Application PCT/US14/71314 (designating the UnitedStates), titled “MULTI-ZONE EC WINDOWS” and filed on Dec. 18, 2014,which claims benefit of and priority to U.S. patent application Ser. No.14/137,644, titled “MULTI-ZONE EC WINDOWS,” filed on Dec. 20, 2013; bothof which are hereby incorporated by reference in their entireties andfor all purposes.

This application is also a continuation-in-part application of U.S.patent application Ser. No. 15/094,897, filed on Apr. 8, 2016 and titled“MULTI-ZONE EC WINDOWS,” which is a continuation application of U.S.patent application Ser. No. 14/137,644 (now U.S. Pat. No. 9,341,912),filed on Dec. 20, 2013 and titled “MULTI-ZONE EC WINDOWS;” all of whichare hereby incorporated by reference in their entireties and for allpurposes.

U.S. patent application Ser. No. 14/137,644 is a continuation-in-partapplication of International Application PCT/US13/069913 (designatingthe United States), filed on Nov. 13, 2013 and titled “MULTI-ZONE ECWINDOWS,” which claims benefit of and priority to U.S. ProvisionalPatent Application No. 61/725,980, filed on Nov. 13, 2012 and titled“MULTI-ZONE EC WINDOWS” and to U.S. Provisional Patent Application No.61/740,651, filed on Dec. 21, 2012 and titled “MULTI-ZONE EC WINDOWS;”all of which are hereby incorporated by reference in their entiretiesand for all purposes.

U.S. patent application Ser. No. 14/137,644 is also acontinuation-in-part application of International ApplicationPCT/US13/031098, filed on Mar. 13, 2013 and titled “PINHOLE MITIGATIONFOR OPTICAL DEVICES,” which claims benefit of and priority of U.S.Provisional Patent Application No. 61/610,241, filed on Mar. 13, 2012and titled “PINHOLE MITIGATION FOR OPTICAL DEVICES;” all of which arehereby incorporated by reference in their entireties and for allpurposes.

FIELD

Embodiments disclosed herein relate generally to optical devices, andmore particularly to methods of fabricating optical devices andparticularly to electrochromic (EC) windows having multiple tintingzones.

BACKGROUND

Electrochromism is a phenomenon in which a material exhibits areversible electrochemically-mediated change in an optical property whenplaced in a different electronic state, typically by being subjected toa voltage change. The optical property is typically one or more of tint,transmittance, absorbance, and reflectance. For example, one well knownelectrochromic material is tungsten oxide (WO₃). Tungsten oxide is acathodically tinting electrochromic material in which a tintingtransition, bleached (untinted) to blue, occurs by electrochemicalreduction. When electrochemical oxidation takes place, tungsten oxidetransitions from blue to a bleached state.

Electrochromic materials may be incorporated into, for example, windowsfor home, commercial and other uses. The tint, transmittance,absorbance, and/or reflectance of such windows may be changed byinducing a change in the electrochromic material, that is,electrochromic windows are windows that can be darkened and lightenedreversibly via application of an electric charge. A small voltageapplied to an electrochromic device of the window will cause it todarken; reversing the voltage causes it to lighten. This capabilityallows control of the amount of light that passes through the windows,and presents an opportunity for electrochromic windows to be used asenergy-saving devices.

While electrochromism was discovered in the 1960s, electrochromicdevices, and particularly electrochromic windows, still unfortunatelysuffer various problems and have not begun to realize their fullcommercial potential despite much recent advancement in electrochromictechnology, apparatus, and related methods of making and/or usingelectrochromic devices.

SUMMARY

Thin-film devices, for example, electrochromic devices for windows, andmethods of manufacturing are described. Embodiments includeelectrochromic window lites having two or more tinting (or coloration)zones, where there is only a single monolithic electrochromic device onthe lite. Certain embodiments include constructs, e.g. laminates, IGUsand the like, that have two EC lites, panes, where one of the panes hasEC zones, and the other pane may have a monolithic EC device coating oralso be a zoned EC coating. Tinting zones are defined by virtue of themeans for applying potential to the device and/or by a resistive zonebetween adjacent tinting zones. For example, sets of bus bars areconfigured to apply potential across separate zones (areas) of thedevice and thereby tint them selectively. The advantages include novisible scribe lines in the viewable area of the EC window due to, e.g.,cutting through the EC device to make separate devices that serve astinting zones. Embodiments that include two EC panes may include amulti-zone EC pane where the zones are formed by cutting through the ECdevice coating, i.e. the other EC pane is used to mask or otherwiseconceal or ameliorate the visual distraction caused by the through cutson the other pane.

One embodiment is an electrochromic window lite including a monolithicEC device on a transparent substrate, the monolithic EC device includingtwo or more tinting zones, each of said two or more tinting zonesconfigured for operation independent of the others and each having apair of associated bus bars, where the two or more tinting zones are notseparated from each other by isolation scribes. That is, the EC devicestack is not cut through, but rather is intact as a monolithic device.For example, there may be two tinting zones on the lite and theassociated bus bars arranged are located at opposing edges of the lite(e.g., vertically oriented), wherein a set of bus bars is associatedwith each of the two tinting zones.

Bus bars may be configured to enhance coloring of tinting zones. Incertain embodiments, bus bars have varying width along their length; thevarying width of the bus bars may enhance the tinting front and/orpromote selective tinting in a particular tinting zone via voltagegradients. In other embodiments, bus bars may be composites, having bothhigh electrically conductive regions and resistive regions, configuredto enhance tinting fronts and/or promote selective tinting in aparticular tinting zone via voltage gradients. One embodiment isdirected to an electrochromic window lite comprising a monolithic ECdevice on a transparent substrate and at least one pair of lengthwisevariable bus bars configured to produce a tint gradient zone on themonolithic EC device when energized.

In certain embodiments, the two or more tinting zones are separated by aresistive zone which inhibits, at least partially, the flow ofelectrons, ions or both across the resistive zone. Resistive zones may,e.g., be parallel to bus bars and/or orthogonal to bus bars. Resistivezones may include modification of the EC device and/or one or bothtransparent conductor layers (TCOs) of the EC device. Monolithic EClites having two or more tinting zones may be integrated into insulatingglass units (IGUs) and/or laminates (singly or as part of an IGU). Themate lite may or may not also be an electrochromic lite, and may or maynot also have tinting zones.

One embodiment is directed to an electrochromic window lite comprising amonolithic EC device disposed on a transparent substrate and a resistivezone. The monolithic EC device is comprised of first and secondtransparent conductor layers and an EC stack between the first andsecond transparent conductor layers. The resistive zone in one of thefirst and second transparent conducting layers. The resistive zone has ahigher electrical resistance than a portion of the one of the first andsecond transparent conducting layers outside the resistive zone. In onecase, the resistive zone is a linear region in the one of the first andsecond transparent conducting layer with thinner or absent material.

Certain aspects of the disclosure pertain to an electrochromic windowlite that may be characterized by the following features: a monolithicEC device on a transparent substrate, the monolithic EC devicecomprising: two or more tinting zones, each of the two or more tintingzones configured for operation independent of the others and having anassociated pair of bus bars. In certain embodiments, the two or moretinting zones contain only a partial cut through the uppermost TCO ofthe monolithic EC device to form a resistive zone between each of saidtwo or more tinting zones. An associated pair of bus bars means thateach zone may have a pair of bus bars that are exclusive to that zoneand not shared with any other zone, or two or more zones may share acommon bus bar, but in either case no two zones share the same pair ofbus bars.

In certain embodiments, the associated bus bars located at opposingedges for each of the two tinting zones. In certain embodiments, theelectrochromic window lite is incorporated into an insulated glass unit,which may have a mate lite that is (i) not an electrochromic lite or(ii) a monolithic electrochromic lite with a single tinting zone, or(iii) a monolithic electrochromic lite with two or more tinting zones(where the tinting zones of the mate lite may be aligned with those ofthe electrochromic window lite), or (iv) an electrochromic lite withthree or more tinting zones. In such embodiments, the electrochromicwindow lite may be configured to tint in one or more tinting zones to<1% T.

In some implementations, the resistive zone substantially spans acrossthe monolithic EC device. In some implementations, the resistive zone isbetween about 1 nm wide and about 10 nm wide. In certain embodiments,the resistive zone is formed by removing between about 10% and about 90%of the uppermost TCO material along the resistive zone. As an example,the resistive zone may be formed by laser irradiation of the uppermostTCO. As a further example, each of the two or more tinting zonesassociated bus bars are formed by laser irradiation during formation ofthe resistive zone by cutting through a single bus bar.

Other aspects of the disclosure pertain to methods of forming amonolithic EC device comprising two tinting zones, where the methods maybe characterized by the following operations: (a) forming the monolithicEC device; (b) applying a single bus bar to the top TCO of themonolithic EC device; (c) cutting through the single bus bar along itswidth; and, (d) cutting at least part way through the top TCO, but notthrough the electrode layer adjacent to the top TCO, to form a resistivezone between the two tinting zones. In certain embodiments, operation(c) forms separate bus bars for each of the two tinting zones from thesingle bus bar. In some implementations, operations (c) and (d) areperformed in a single cutting step.

In some implementations, the resistive zone substantially spans thewidth of the monolithic EC device. In certain embodiments, the resistivezone is between about 1 nm wide and about 10 nm wide. In certainembodiments, the resistive zone is formed by removing between about 10%and about 90% of the uppermost TCO material along the resistive zone. Asan example, the resistive zone may be formed by laser irradiation of theuppermost TCO.

Zoning in EC windows may be used in certain applications, e.g., a windowis made darker at the top to control glare, while the bottom portion islighter so user view is maintained and more light still enters the roomthan would otherwise with a monolithic EC coating fully tinted to reduceglare.

Another aspect of the disclosure concerns electrochromic window lites(panes) characterized by the following features: an EC device on atransparent substrate, the EC device comprising bus bars; a region ofthe transparent substrate that is not covered by the EC device, wherethe region capable of providing, when not mitigated, a bright spot orbright region when the EC device is tinted; and an obscuring materialover the region, wherein the material has a lower transmittance than thesubstrate. In some embodiments, the region is a pinhole, a scribe line,or an edge line.

Yet another aspect of the disclosure concerns methods of obscuring apotentially bright area produced by a region of a transparent substratethat is not covered by an EC device. Such methods may be characterizedby the following operations: (a) providing an electrochromic lite havingthe EC device coating on a substrate; (b) identifying a site of thepotentially bright area on the substrate; and (c) applying an obscuringmaterial to the site. The obscuring material has a lower transmittancethan the substrate. In certain embodiments, the region is a pinhole, ascribe line, or an edge line.

These and other features and advantages will be described in furtherdetail below, with reference to the associated drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The following detailed description can be more fully understood whenconsidered in conjunction with the drawings in which:

FIG. 1 depicts fabrication of an IGU with an EC lite and associatedtinting schemes.

FIGS. 2A and 2B depict an IGU having an EC lite with two tinting zonesdelineated by laser scribe, and associated tinting schemes,respectively.

FIGS. 3A and 3B depict fabrication of an IGU with an EC lite havingtinting zones configured on a monolithic EC device and associatedtinting schemes, respectively.

FIG. 3C depicts various tinting schemes as a function of tinting frontof tinting zones.

FIGS. 3D and 3E depict fabrication of an IGU having two EC lites, whereeach of the EC lites has two tinting zones, and associated tintingschemes, respectively.

FIGS. 4A-C depict fabrication of an IGU with an EC lite and associatedtinting schemes, respectively.

FIGS. 4D-H depict EC lites, each having a gradient tinting zone.

FIGS. 5A and 5B depict fabrication of an IGU with an EC lite andassociated tinting schemes, respectively.

FIG. 5C depicts a perspective and a cross section of an EC device havingtwo tinting zones separated by a resistive zone.

FIG. 5D depicts a perspective and a cross section of an EC device havingtwo tinting zones by virtue of a resistive zone.

FIG. 5E shows graphs of V_(TCL) for two transparent conducting oxidelayers of an EC device configured with a resistive zone created byinhibiting the electrical conductivity of only one of the transparentconducting oxide layers.

FIG. 5F depicts a tinting pattern of the EC lite described in relationto FIG. 5C.

FIGS. 5G to 5K depict EC devices configured with a resistive zonecreated by inhibiting the electrical conductivity of only one of thetransparent conducting oxides.

FIG. 6A depicts a resistive zone establishing a closed perimeterdefining a separate tinting zone.

FIG. 6B depicts a resistive zone establishing an open perimeter defininga separate tinting zone.

FIG. 7 depicts using resistive zones for multi EC litepatterns/displays.

FIG. 8 depicts a building facade using resistive zones to create wordsand/or ornamental designs.

FIG. 9 depicts a building facade using gradient zoning across multipleIGUs.

DETAILED DESCRIPTION

Certain embodiments are directed to optical devices, that is, thin-filmdevices having at least one transparent conductor layer. In the simplestform, an optical device includes a substrate and one or more materiallayers sandwiched between two conductor layers, one of which istransparent. In one embodiment, an optical device includes a transparentsubstrate and two transparent conductor layers. Certain embodimentsdescribed herein, although not limited as such, work particularly wellwith solid state and inorganic electrochromic devices.

FIG. 1 depicts fabrication of an IGU, 120, with an EC lite, 100, whichincludes a monolithic EC device and associated pair of bus bars, 105,which energize the device each via a transparent conductor, the pair oftransparent conductors sandwich the EC materials between them so that apotential can be applied across the device materials. The IGU isfabricated by combining EC lite 100 with a spacer, 110, and a mate lite,115, along with the appropriate sealants and wiring (not shown) to thebus bars. In some applications, a second set of spacer and mate lite maybe added (i.e. Triple Pane IGU). The two mate lites may be of differenttypes. As depicted on the bottom half of FIG. 1, the IGU can betransparent (left), tinted to an intermediate state (middle) or fullytinted (right). However, there is no possibility of tinting the viewablearea of the lite in different areas or “zones.” Conventional technologydoes exist to achieve this end, however.

FIG. 2A depicts an IGU, 220, having an EC lite, 200, with two tintingzones delineated by laser scribe, 225. Each tinting zone has anassociated pair of bus bars, 205 and 207, respectively. The EC lite 200may be incorporated into an IGU, 220, as described in relation toFIG. 1. Scribe line 225 cuts through both of the transparent conductorlayers which sandwich the electrochromic materials, along with the ECdevice layer(s), so that there effectively two EC devices, onecorresponding to each tinting zone, on the EC lite 200. Scribe line 225may not be visually discernible when the EC lite is not tinted, asdepicted in FIG. 2A, i.e. in the untinted state (bleached or neutralstate).

FIG. 2B depicts three possible tinting schemes of IGU 220. As shown, IGU220 may have the top zone tinted and the bottom zone untinted (left),the top zone untinted and the bottom zone tinted (middle) or both thetop and bottom zones tinted (right). Although such windows offerflexibility in tinting, when both zones are tinted, scribe line 225 isvisually discernible and is unattractive to an end user because there isa bright line across the middle of the viewable area of the window. Thisis because the EC material in the area has been destroyed and/ordeactivated from the scribe line that cut through the device. The brightline can be quite distracting; either when one is looking at the windowitself, or as in most cases, when the end user is trying to view thingsthrough the window. The bright line against a tinted background catchesone's eye immediately. Many approaches have been taken to create tintingzones in optical devices, but they all involve some sort of physicalsegmentation of a monolithic optical device into two or moreindividually operable devices. That is, the functionality of the ECdevice is destroyed along the scribe line, thus effectively creating twodevices from a monolithic single device. Certain embodiments describedherein avoid destroying the EC device function between adjacent tintingzones.

One approach to overcoming the visually distracting bright line createdby a laser scribe in the viewable area of an EC lite is to apply atinted material to the lite, e.g. on the scribe line or on an opposingside of the lite, in order to obscure or minimize the light passingthrough the scribe area. Thus, when tinting zones adjoining the scribeare tinted, the scribe line will be less discernible to the end user.When neither of the adjoining tinting zones is tinted, the tintedmaterial in the scribe line area will be almost or completelyindiscernible because it is a thin tinted line against a large untintedbackground, which is harder to see than a bright line against a tintedbackground. The thin tinted line need not be opaque, a limited amount ofabsorption of the visible spectrum can be used, e.g., absorption thatwill tone down the bright line created when the full spectrum emanatesthrough scribe line 225. Methods for obscuring pinhole defects inoptical devices are described in, for example, described in U.S.Provisional Patent Application Ser. No. 61/610,241, filed Mar. 13, 2012,and described in PCT Application Serial No. PCT/US2013/031098 filed onMar. 13, 2013, which are both hereby incorporated by reference in theirentirety. Whether obscuring pin holes, scribe lines, edge lines, or thelike, the methods obscure bright areas on EC devices, e.g. by applyingtinted material to such areas to make them harder to see to the enduser. Edge lines exist where a coating such as a monolithicelectrochromic coating, does not extend to the spacer of an IGU (e.g.,element 110 of FIG. 2A). In this region, a bright line or wider area isvisible when viewing the IGU directly. As understood by those of skillin the art, the obscuring methods described in the present applicationand in PCT/US2013/031098 have equal applicability to pin holes, edgelines, scribe lines, and the like. The methods described in theaforementioned patent application are particularly useful for obscuringscribe or edge lines in the visible area of an optical device such as anEC device. One embodiment is a method of obscuring a scribe line in theviewable area of an EC window, the method including applying a methodused to obscure pinholes as described in the aforementioned US/PCTPatent application. For example, one method includes applying a tintedmaterial to the scribe line and optionally the area adjacent the scribeline. In another example, the glass at the bottom of the scribe linetrench (and optionally some adjoining area) is altered so as to diffuselight that passes therethrough, thus ameliorating the “bright line”effect.

Tinting Zones

As discussed above, certain embodiments described herein avoiddestroying the EC device functionality between adjacent tinting zones.Though scribe lines may be visually obscured by application of tintedmaterials to the lite as described above, the inventors have found thatit may be often preferable to maintain the functional integrity of amonolithic EC device, rather than scribe it into discrete devices andthus conventional tinting zones. The inventors have discovered thattinting zones may be created by: 1) configuring the powering mechanism(e.g. bus bars, wiring thereto and associated powering algorithms) ofthe optical device appropriately, 2) configuring the EC device such thatadjacent tinting zones are separated by a resistive zone, or 3)combination of 1) and 2). For example, number 1) may be achieved byappropriately configuring one or more bus bars such that they can beactivated independently of other bus bars on the same monolithic ECdevice. Thus tinting zones are created without the need to physicallyseparate individual EC devices to create corresponding tinting zones. Inanother example, a resistive zone allows coloration and bleaching ofadjacent tinting zones on a single EC device without destroyingfunctionality in the resistive zone itself. A resistive zone can referto an area of the monolithic optical device, e.g. an EC device, wherethe function is impaired but not destroyed. Typically, the functionalityin the resistive zone is merely slowed relative to the rest of thedevice. Impairment might include diminished capacity for ion movement inone or more of the layers of the EC device and/or reduced density of theions. The change in EC stack properties and/or ion density maybe doneduring deposition/fabrication of the EC stack or post-deposition througha thermal/laser irradiation treatment. For example, one or more ECdevice layers may be made denser than it otherwise would be in the bulkfunctioning device and therefore be able to hold fewer ions and/or allowion passage through the denser material, and therefore color lessintensely than the bulk device, but still function. A resistive zone isachieved in at least one of the following ways: i) the electricalresistivity of one or both of the transparent conductor layers isimpaired, ii) one or both of the transparent conductor layers is cut,without cutting through the optical device stack therebetween, iii) thefunction of the optical device stack (not including the transparentconductor layers) is impaired, and iv) combinations of i)-iv). Forexample, a resistive zone may be created where one or both of thetransparent conductor layers is fabricated thinner or absent, e.g. alonga linear region, so as to increase electrical resistivity along thelinear region of the resistive zone. In another example, one of thetransparent conductor layers may be cut along the width of the device,while the other transparent conductor is left intact, either of uniformthickness or thinner, along the resistive zone. In yet another example,the function of the EC device may be inhibited along a line, so that itresists ion transport, while the transparent conductor layers may or maynot be altered along the same line. Resistive zones are described inmore detail below in terms of specific, but non-limiting examples. Ifthe resistive zone is in one of the transparent layers, the othertransparent layer may be left intact (e.g., uniform composition andthickness).

Configuring Powering Mechanism of EC Devices

One embodiment is an electrochromic window lite including a monolithicEC device on a transparent substrate, the monolithic EC device includingtwo or more tinting zones, each of the two or more tinting zonesconfigured for operation independent of the others and having anassociated pair of bus bars. In certain embodiments, the two or moretinting zones are not separated from each other by isolation scribes;that is, the EC device and associated transparent conductors do not haveisolation scribes that cut through any of these layers. For example,there may be two tinting zones on the EC lite and two pairs of bus bars,wherein each pair is associated with a tinting zone and both pairs arelocated at or near opposing edges of the EC lite e.g., the bus bars maybe vertically oriented at or near opposing vertical edges with a set ofbus bars for each of the two tinting zones. Such lites may be integratedinto insulating glass units (IGUs).

FIG. 3A depicts fabrication of an IGU, 300, with an EC lite, 305 havingtwo tinting zones (upper and lower tinting zones) configured on amonolithic EC device. In this example, there are no laser scribes orother physical sectioning (e.g. bifurcation) of the monolithic EC deviceor transparent conductor layers on the lite. Each of bus bar pairs, 205and 207, is configured to energize independently of each other. Thus,referring to FIG. 3B, IGU 300 has three tinting schemes besides theuntinted state (bleached or neutral state) depicted in FIG. 3A. FIG. 3Bshows these three tinting schemes where the top zone may be tinted whilethe bottom zone is not (left), the bottom zone may be tinted while thetop zone is not (middle), or both zones may be tinted (right). Incontrast to an EC lite having two distinct EC devices by virtue of beingdivided by a scribe line, each tinting zone of lite 305, when tinted,has a “tinting front” 310. A tinting front can refer to an area of theEC device where the potential applied across the devices TCOs by the busbars reaches a level that is insufficient to tint the device (e.g. bymovement of ions through the layers of the device to balance charge).Thus, in the example depicted, the tinting front 310 corresponds roughlyto where the charge is bleeding off into the area of the transparentconductor that is between the pair of bus bars that are not energized.

The shape of a tinting front may depend upon the chargingcharacteristics of the transparent conductors, the configuration of thebus bars, wiring and powering thereto, and the like. The tinting frontmay be linear, curved (convex, concave, etc.), zigzag, irregular, etc.For example, FIG. 3B depicts the tinting front 310 as a linearphenomenon; that is, the tinting front 310 is depicted as located alonga straight line. As another example, FIG. 3C depicts various tintingschemes as a function of tinting front of each of the tinting zones, inthis case lower and upper tinting zones. In the illustrated example, thetinting front is curved (e.g., concave or convex) along the tintingfront. In certain embodiments, it may be desirable that when bothtinting zones are tinted, the tinting of the EC lite is total anduniform. Thus a convex tinting front may be desirable, so acomplimentary concave tinting front may be used in an adjacent zone, oranother convex tinting front may be used to ensure sufficient chargereaches the entire device for uniform tinting. In certain cases, thetinting front may not be a clean line as depicted in FIGS. 3B and 3C,but rather have a diffuse appearance along the tinting front due to thecharge bleeding off into the adjacent tinting zone which is not poweredat the time.

In the case where two adjacent zones are tinted, but one zone's tintinglevel is different than the other, e.g., where one zone is tinted to 5%T and the other adjacent zone tinted to 20% T, there may be nonoticeable tinting front. That is, the two zones' tinting may blendsinto each other for a uniform gradient tinting appearance, e.g.resembling a shading effect, where the coloration is darkest in one zoneand appears to gradually lighten into and including the adjacent zone.In the event that individual tinting zones on a monolithic EC devicehave aesthetically unappealing coloration fronts, one may apply tintingvoltages to all zones, but where the tinting voltages to individualzones are the same or different. One embodiment is a method ofcontrolling a monolithic EC device coating, including tinting twoadjacent zones simultaneously by virtue of selective application ofvoltage to different areas of the monolithic EC device.

In certain embodiments, when the EC lite with tinting zones isincorporated into an IGU or a laminate for example, the mate lite mayalso be an EC lite, having tinting zones or not. Insulated glass unitconstructions having two or more (monolithic) EC lites are described inU.S. Pat. No. 8,270,059, which is hereby incorporated by reference inits entirety. Having two EC lites in a single IGU has advantagesincluding the ability to make a near opaque window (e.g. privacy glass),where the percent transmission (% T) of the IGU is <1%. Also, if the EClites are two-state (tinted or bleached) there may be certain tintingcombinations made possible, e.g. a four-tint-state window. If the EClites are capable of intermediate states, the tinting possibilities maybe virtually endless. One embodiment is an IGU having a first EC litehaving two or more tinting zones and a mate lite that is a monolithic EClite. In another embodiment, the mate lite also has two or more tintingzones. In this latter embodiment, the tinting zones may or may not bethe same in number or aligned with the tinting zones of the first EClite with which it is registered in the IGU. Exemplary constructsillustrating these descriptions follow.

FIG. 3D depicts fabrication of an IGU, 325, having two EC lites, 305 and320, where each of the EC lites has two tinting zones, each of thetinting zones created by appropriately configured bus bar pairs, 205 and207 at or near two opposing edges. In this illustrated example, thetinting zones of EC lites 305 and 320 are registered, that is, they arealigned with each other and of the same area, but this need not be theconfiguration. For example, the tinting fronts from opposing EC lites305 and 320 could overlap each other when tinted in another embodiment.FIG. 3D depicts IGU 325 in an untinted state (bleached or neutralstate). Also, each of the tinting zones is capable of only two states,tinted or bleached. Even so, this enables a wide range of tintingschemes for IGU 325. Besides the untinted state, IGU 325 is capable ofmany tint states (e.g., eight tint states). FIG. 3B depicts three of thepossible tint states (i.e. where one EC lite of IGU 325 is tinted in oneof the three configurations shown in FIG. 3B). FIG. 3E depicts anotherfive possible tint states for IGU 325. If the top tinting zones of bothEC lites are tinted simultaneously, and the bottom two zones are not,then the top half of the IGU is very dark, while the bottom is untinted(top left IGU). If both of the top tinting zones are not tinted, and thebottom two zones are tinted, then the bottom half of the IGU is verydark, while the top is untinted (top middle IGU). If all four zones ofthe EC lites are tinted, then the entire window is very dark (top rightIGU). For example, the combined tinting of all tinting zones in tworegistered EC lites can achieve <1% T. If one of the top zones in the EClites is tinted and both of the bottom zones are tinted, then the tintstate on the bottom left of FIG. 3E is created. Likewise, if one of thebottom zones is tinted and both of the top zones are tinted, then thetint state on the bottom right of FIG. 3E is created.

One embodiment is an IGU having two or more EC lites, wherein at leasttwo of the two or more EC lites includes multiple tinting zones asdescribed herein. The tinting zones may be formed physically in thecoating, i.e. by bifurcation of a monolithic coating, forming aresistive zone in a monolithic EC coating, or both; or a monolithiccoating with no resistive zones may be controlled by selectiveapplication of voltages to different areas to form tinting zones. Oneembodiment is an IGU or laminate having two or more EC lites, where afirst of the two or more EC lites includes multiple tinting zonescreated by conventional isolation scribes, and a second of the two ormore EC lites includes tinting zones as described herein by techniquesother than isolation scribes. One embodiment is an IGU or laminatehaving two or more EC lites, where a first of the two or more EC litesincludes multiple tinting zones, and a second of the two or more EClites includes a monolithic EC coating without tinting zones.

Configurations such as those depicted in FIGS. 3B and 3E may beparticularly useful in applications such as creating day lighting zonesvs. occupant (glare) control zones. The day lighting zones may also betinted but at lower tint level than the glare control zones for theoptimal user experience, e.g. day lighting zones may be tinted to %Tvis˜4%-30% while the glare control zones may be tinted to %Tvis˜0.1-1%. Day lighting transoms are very common. For example,creating “virtual transoms” with a piece of glass and thus removing theframe and associated glazier labor has a cost benefit as well as bettersight lines. Also, having a variety of tint states such as thosedepicted in FIGS. 3B and 3E allows for customization of room lightingbased on the amount and location of the sun striking individual windows.

Certain embodiments pertain to methods of transitioning an EC litehaving two or more tinting zones. In one embodiment, an EC lite havingthree or more tinting zones is transitioned across the three or moretinted zones from a first zone at one edge of the device, to a secondadjacent tinting zone, and then to a third tinting zone, adjacent to thesecond zone. In other words, the tinting zones are used to give theeffect of drawing a physical shade across the window, without actuallyhaving a physical shade, since EC windows may eliminate the need forphysical shades. Such methods may be implemented with conventional zonedEC lites or those described herein. This is illustrated in FIGS. 4A-Cwith respect to an EC lite of an embodiment.

Referring to FIG. 4A, an EC lite, 400, is configured with a first set ofbus bars, 405, a second set of bus bars 407, and a third set of busbars, 409. The three sets of bus bars are configured so as to createthree tinting zones, respectively. Although EC lite 400 in FIG. 4A isincorporated into an IGU, 420, using a spacer 410 and a mate lite 415,lamination to a mate lite (EC lite or otherwise) or use as a single EClite is also possible.

Referring to FIG. 4B, assuming that each of the tinting zones is tintedas a two-state zone, then the three tinting zones may be activatedsequentially, e.g. from top to bottom as depicted, to create a physicalshade effect, i.e. as if one were lowering a roller shade or drawing aRoman shade over the window. For example, the top zone may be fullytinted, then the second zone may be fully tinted, finally the third zonemay be fully tinted. The tinting zones could be sequentially tinted fromthe bottom up or in the middle and then the upper and lower zonestinted, depending upon the desired effect.

Another method is to tint the tinting zones as described with respect toFIG. 4B, except that before transition in a particular tinting zone iscomplete, transition in an adjacent tinting zone begins, which can alsocreate a shading effect. In the illustrated example of FIG. 4C, the toptinting zone's tinting is initiated (top left), but before tinting iscomplete in the top zone, the middle zone's tinting is initiated. Oncethe top zone's tinting is complete, the middle zone's tinting is not yetcomplete (top center). At some point during the transition of the middlezone, the bottom zone's tinting is initiated. Once the middle zone'stinting is complete, the bottom zone's tinting is not yet complete (topright), thus the top and middle zones are fully tinted and the bottomzone's tinting is yet to be completed. Finally, the bottom zone is fullytinted. Using tinting zones with intermediate state capability, ratherthan two-state “tint or not,” will increase the possible variations oftinting schemes.

Lengthwise Variable Bus Bars

In certain embodiments, an EC lite may be configured to have one or moretint gradient zones. In these embodiments, the EC lite has an EC device,such as, e.g., a monolithic EC device on a transparent substrate, andalso has at least one pair of bus bars with geometry and/or materialcomposition that varies along their lengths to vary electricalresistance lengthwise (lengthwise variable bus bars). This variation inresistance can produce a lengthwise gradient in the voltage applied tothe EC device supplied across bus bars (V_(app)) and a lengthwisegradient in the local effective voltage (V_(eff)) in the EC device. Theterm V_(eff) refers to the potential between the positive and negativetransparent conducting layers at any particular location on the ECdevice. The lengthwise gradient of the V_(eff) may generate acorresponding tint gradient zone that varies lengthwise in a regionbetween the pair of bus bars when energized. In these embodiments, thelengthwise variable bus bars will have resistance profiles along theirlengths that are functions of both the local bus bar geometry andresistivity. In certain embodiments, the bus bars are designed so thatthe resistance is lowest at one end of the bus bar and highest at theother end of the bus bar. Other designs are possible, such as designswhere the resistance is lowest in the middle of a bus bar and highest atthe ends of the bus bar. A description of voltage profiles in various ECdevices powered by bus bars can be found in U.S. patent application Ser.No. 13/682,618, titled “DRIVING THIN FILM SWITCHABLE OPTICAL DEVICES,”filed on Nov. 20, 2013, which is hereby incorporated by reference in itsentirety.

EC devices configured, e.g., as described in relation to FIGS. 4D and4E, in addition to being capable of tinting in a gradient fashion asdepicted, may also, e.g. upon application of sufficient voltage, tint toa uniform coloration. For example, a maximum (and uniform) tinting maybe achieved across the monolithic device coating by application ofsufficient voltage using bus bars also configured to apply a gradientvoltage (and give the gradient tinting shown).

The local material composition of a bus bar may determine its localresistivity. It is contemplated that the bus bar material composition,and therefore the bus bar resistivity may vary along the length of thebus bar in certain embodiments. The resistivity can be tailored based onvarious compositional adjustments known to those of skill in the art.For example, resistivity can be adjusted by adjusting the concentrationof a conductive material in the bus bar composition. In someembodiments, bus bars are made from a conductive ink such as a silverink. By varying the concentration of silver in the ink along the lengthof the bus bar, one can produce a bus bar in which the resistivitylikewise varies along the length. The resistivity can also be varied byother compositional adjustments such as the local inclusion of resistivematerials in the bus bar or the variation of the composition of aconductive component to adjust its resistivity. Slight variations incomposition can change the resistivity of certain conductive materialssuch as conductive polymers. In certain embodiments, the electricalconductivity of the bus bar material is constant, but the thicknessand/or width of the bus bar varies along its length.

The value of the voltage that can be applied at any position on the busbar is a function of the location where the bus bar connects to anexternal power source and the resistance profile of the bus bar. A busbar may be connected to the source of electrical power at locationswhere the bus bar has least resistance, although this is not required.The value of the voltage will be greatest at the locations where thepower source connection attaches to the bus bars. The decrease involtage away from the connection is determined by the distance from theconnection and the resistance profile of the bus bars along the pathfrom the connection to the point where voltage is measured. Typically,the value of voltage in a bus bar will be greatest at the location wherean electrical connection to the power source attaches and least at thedistal point of the bus bar. In various embodiments, a bus bar will havelower electrical resistance at an end proximal to the connection to theelectrical source and a higher resistance at a distal end (i.e. theresistance is higher at the distal end than at the proximal end).

Each of the lengthwise variable bus bars may have linearly, stepped, orotherwise varying geometry and/or material composition along its length.For example, a bus bar with lengthwise-varying geometry may have itswidth, height, and/or other cross-sectional dimension linearly taperingfrom the proximal end to the distal end. As another example, a bus barmay be comprised of multiple segments with stepwise decreasing widths orother dimensions from the proximal end to the distal end. In yet anotherexample, a bus bar may have a material composition that varieslengthwise to increase electrical resistivity between proximal anddistal ends.

FIGS. 4D and 4E depict EC lites, 425 and 435 respectively, each having amonolithic EC device on a transparent substrate and a pair of bus bars.The width of each of the bus bars varies along its length. Thisgeometric lengthwise variation in the bus bars may produce a tintgradient zone (gradient in lengthwise direction) on the monolithic ECdevice when energized.

FIG. 4D depicts an EC lite, 425, including bus bars 430. Each of the busbars 430 has a varying width along its length that linearly taperslengthwise. In certain embodiments, the variation in width between thetwo ends may be between about 10% and about 100% from the average widthover the length of the bus bar. In one embodiment, the variation inwidth may be between about 10% and about 80% from the average width overthe length of the bus bar. In another embodiment, the variation in widthmay be between about 25% and about 75% from the average width over thelength of the bus bar. In this example, not drawn to scale, the bus bars430 are widest at the top of EC lite 425 and linearly taper lengthwiseto their thinnest width near the bottom of lite 425. Because of thevarying width, bus bars 430, when energized, establish a voltagegradient. For example, when energized, bus bars 430 have their highesteffective voltage at the top, and their lowest voltage at their bottomportion; a voltage gradient is established along the bus bars. Asdepicted in the right portion of FIG. 4D, a corresponding tintinggradient is established by virtue of the voltage gradient. Thus a tintgradient zone is established. Bus bars of varying width can be used inone or more zones of an EC lite having two or more zones as describedherein. In this illustrated example, a single tint gradient zone isestablished across an EC lite. Although a linearly tapered width isillustrated in FIG. 4D, a non-linearly tapered width can be used inother cases.

In certain embodiments, the tapering of the bus bars need not be asmooth taper. For example, a bus bar may have a stepped down width alongits length (i.e. stepwise width variation along its length). FIG. 4Edepicts an EC lite, 435, having a monolithic EC device and bus bars thathave stepped widths along their lengths. Each bus bar has three segmentswith stepped down widths along its length. Each bus bar has a firstwidth that spans a first portion, 440, of the length of the bus bar.Adjacent to the first portion, is a second portion, 445, of the lengthof each bus bar. The second portion has a second width shorter than thefirst width. Finally, adjacent to the second portion and having a thirdwidth, is a third portion, 450 of each bus bar. The net tinting gradienteffect may be the same as or similar to the smooth linearly taper busbars described in relation to FIG. 4D. One of ordinary skill in the artwould appreciate that varying the width of the bus bars can be done inother patterns, such as thicker in the middle than at the ends, etc.without escaping the scope of embodiments described herein, that is foran EC lite having bus bars of varying widths configured to create one ormore tint gradient zones, and corresponding tinting effects, on amonolithic EC device.

Electrically Resistive Bus bars

In certain embodiments, a bus bar with uniform cross-section andelectrical conductivity characteristics is used to create the requiredelectrical gradient from one end of the bus bar to the other end. Thisis achieved by taking advantage of voltage drop along a bus bar. Thatis, a bus bar of sufficient resistivity, e.g. a sufficiently thin busbar of highly conductive material or a bus bar made of more resistive,though still conductive material, such that there is a voltage dropalong the bus bar's length when voltage is applied to one end. It can beshown that:

ΔV_(L)=(R_(B)*J*W₀*L)²/2 where:

-   -   ΔV_(L) is voltage drop along Bus bar at a distance L from point        of application of power    -   R_(B) is the resistance per unit length of the Bus bar    -   J is the leakage current density of the EC window    -   W₀ is the width of the EC window        Thus, for a window where the bus bar is powered at one end only,        if:        RB>(ΔV/L₀)*(2/I_(EC)) where:    -   ΔV is the required voltage drop along the bus bar    -   I_(EC) is the net current draw for the EC device    -   L₀ is the length of the EC window

Then the electrically resistive bus bar will act as a resistance path inthe circuit and be able to provide adequate drop in voltage along itslength. Since the Transmission of the EC window is proportional to theV_eff, and the drop in the voltage along the Bus bar (ΔV) reduces theV_eff as described previously, the (ΔV/L₀) terms represents the gradientof the shading/Tvis from one end to the other, e.g. a small part (smallL₀) with a large voltage drop along the bus bar from end to the otherwill have a very pronounced Tvis shading/gradient, while for a largepart will need a larger voltage drop along the bus bar to maintain thesame shading along its length. Thus, the bus bar properties, e.g.height, width, material, though having a uniform cross section, can beselected during fabrication to provide the required shading from one endto the other. This enables ease of design/manufacturing to avoidcomplex-geometry bus bars, while still providing a gradient in theoptical properties across the window. For example, one can fabricate athin bus bar that has a voltage drop across its length to create agradient shading.

Dual Powered Bus bar

In certain embodiments described above, the bus bars, particularly thosein the “electrically resistive bus bar” embodiments described inrelation to FIG. 4G, can be powered from one end of the bus bars (asdescribed above) or both ends of each bus bar (as described in relationto FIG. 4H). Powering bus bars from both ends provides additionalcontrol over the gradients/shading of the EC window. For example, asdepicted in FIG. 4H (top left), a voltage is applied to the top ends ofthe two bus bars that power each of the TCO's of the EC device coating.The bottom ends are also in electrical communication through leads(depicted here as “open”). A voltage gradient is established over thelength of the bus bars, in this example substantially equal gradientsacross the bus bars of substantially the same length. This results in avoltage gradient across the TCO's and a corresponding tinting gradientacross the monolithic EC device coating. By using a dual leadconfiguration, one can “flip” the tinting gradient (see FIG. 4H, topright) by applying voltage at the bottom of the bus bars andestablishing the opposite tinting gradient (depicted vertically here).

Referring again to FIG. 4H, bottom, one of ordinary skill in the art cansee that multiple combinations are possible by suitable selections ofV_applied_1, V_applied_2 and bus bar pattern and R_(B). In this example,the top and bottom portions of the EC device are tinted darker than amiddle portion, when V_applied_1 and V_applied_2 are applied to bothends of both bus bars (only one bus bar's application depicted).

In one embodiment, an IGU includes two EC lites, each EC lite having atint gradient zone as described in relation to FIGS. 4D and 4E. In oneembodiment, the tint gradient zone of each EC lite is configured inopposition to each other, that is, one EC lite has a tinting front thatstarts at the opposite side (e.g., edge) of where the tinting front ofthe other EC lite starts. In this embodiment, a unique curtaining effectis established where the tinting fronts approach each other fromopposite sides and cross paths in the middle of the IGU. In one case,when transition is complete in both EC lites, the IGU may have a“privacy glass” tint level, of e.g. <1% T. In another embodiment, eachEC lite may be tinted independently to provide a “top down” tintgradient or “bottom up” tint gradient. In one embodiment, the tintgradient zones of the EC lites are registered together i.e. aligned sothat the tinting fronts of the EC lites start on the same side of theIGU and end at the other opposing side. In this latter embodiment,tinting of the IGU may be done for different tint levels with one lite,e.g., to provide a top down tint gradient of one intensity (absorptiongradient e.g.) for one tint level, and another (darker) tint level oftinting gradient when both lites are tinted. Either of the twoaforementioned IGU embodiments may have their individual EC lites tintedtogether or alternatively tinted asynchronously for yet another shadingeffect that is not possible with conventional monolithic EC devices.

In one embodiment, a bus bar may include an inner portion ofelectrically conductive material with a cross-sectional dimension (e.g.,width) that varies lengthwise, and an outer portion of electricallyresistive material. The outer portion may have geometry which isdesigned to couple and form with the inner portion a uniformcross-section along the length of the bus bar.

In certain embodiments, such as some embodiments described above, anelectrochromic window lite includes a monolithic EC device on atransparent substrate, wherein the EC lite includes at least one pair ofbus bars configured to produce a tint gradient zone on the monolithic ECdevice when energized. In some embodiments, tinting gradients areestablished using bus bars, where each bus bar has at least two portionsthat are highly conductive. The at least two portions are separated by aportion that is more resistive than the highly conductive at least twoportions, while still being electrically conductive. The more resistiveportion is configured adjacent to or overlapping the at least two highlyconductive portions. In this embodiment, the at least two highlyconductive portions are separated, they do not touch, but rather eachonly touches, and is in electrical communication with the more resistiveportion in between them. An electrical power source is configured topower only one portion of the at least two highly conductive portions ofeach of the at least one pair of bus bars. Each of the only one portionof the at least two highly conductive portions is proximate the sameside of the monolithic EC device as the other of the only one portion.One of these embodiments is described in more detail in relation to FIG.4F.

Tint gradient zones can be created using bus bars having varyingmaterial composition along their lengths. For example, FIG. 4F depictsan EC lite, 455, having two bus bars, each configured along opposingedges (e.g., vertically, horizontally, etc.) and parallel to each otheron lite 455. In this example, each bus bar has highly electricallyconductive portions, 460 a, 460 b, and 460 c (collectively, 460), andless electrically conductive portions, 465 a and 465 b (collectively,465). In the illustrated example, less electrically conductive portions,465 a is between highly electrically conductive portions 460 a and 460b, and less electrically conductive portions, 465 b is between highlyelectrically conductive portions 460 b and 460 c. The less electricallyconductive portions, 465 a and 465 b, may be portions of a monolithicbus bar where the conductivity has been reduced by, e.g. changing themorphology of the bus bar material and/or perforating the material, etc.In another example, separate bus bars are used, for example as describedin relation to FIGS. 4A and 4B, and the TCO on which it lies,specifically the area of the TCO between ends of bus bars, acts as aresistive element to slow current flow between proximate bus bar ends.Referring again to the specific example in FIG. 4F, highly electricallyconductive portions 460 a, 460 b, and 460 c may be conventional silverbased conductive bus bar ink, while portions 465 a and 465 b may be aless conductive ink. In this illustrated example, the bus bars may beconnected to an electrical source at the top portion, 460 a, of each busbar. A voltage gradient may be established along the length of the busbars by virtue of the resistive portions 465 a and 465 b. That is, thetop highly conductive portions 460 a may have the highest voltage, andthe middle highly conductive portions 460 b may have a somewhat lowervoltage because the more resistive portions 465 a creates an IR voltagedrop between the middle portions 460 b and portions 460 a. Likewise thebottom-most highly conductive portions 460 c may have the lowest voltagebecause the more resistive portions 465 b lie between them and themiddle highly conductive portions 460 b preventing some of theelectrical current from flowing from middle portion 460 b to lowerportion 460 c. The net effect may be a tint gradient zone, for example,the one depicted in FIG. 4F. Highly electrically conductive portions 460may be of the same or different conductive material, and likewise, lesselectrically conductive portions 465 may be comprised of the same ordifferent conductive material. The key is that portions 465 are lesselectrically conductive than their adjacent neighbors 460. Using thistechnology, a wide variety of voltage and/or resistance patterns may beestablished in order to create corresponding tint gradient zones in anEC lite. In addition, a combination of bus bars of lengthwise varyingwidth and those bus bars configured as described in relation to FIG. 4Fmay be used. For example, each as partners in a bus bar pair and/or inindividual tint gradient zones on an EC lite.

Remotely Controlled Resistive Nodes

In certain embodiments, the less electrically conductive portions, 465have variable resistance whose resistance can be varied between 1 mOhm-1kOhm to dynamically adjust the tint gradient zones, i.e. when no zoningis required, elements 465 are in the low resistance state. That is thebus bar segments 460 and 465, collectively, act as a single bus bar oflow resistitivity. When zoning is desired, elements 465 are switched toa higher resistance state (than bus bar segments 460) when zoning isdesired. The resistance of the element can also be varied to modulatethe gradient in the Tvis (lower resistance for lower gradient). Theelement 465 can be an electronic control element that can modulatedremotely (e.g. wireless/Bluetooth/Zigbee etc.) and can be triggered byautomated EC control intelligence and/or manually by user input. Thecontrol element may be a component of an onboard controller, that is, anEC controller that is integrated with, in, part of the IGU. Such onboardcontrollers are described in U.S. patent application Ser. No. 13/049,750titled “ONBOARD CONTROLLER FOR MULTISTATE WINDOWS,” filed on Mar. 16,2011 and in U.S. patent application Ser. No. 14/951,410 titled“SELF-CONTAINED EC IGU,” filed on Nov. 24, 2015, both of which arehereby incorporated by reference in their entirety.

Different Bus Bar Types on each TCO of an EC Device.

In certain embodiments, the top and bottom TCO bus bar configurationsmay be different, which can be used synergistically to provide even morecontrol over the zoning/gradients. For example, consider a specificcross section (orthogonal to the bus bars) of a monolithic EC devicecoating having bus bars of different configuration along each side. Ifthe voltage profile, gradient, along one bus bar is different than thevoltage profile of the other bus bar, then various tint gradients can beachieved. Thus, with different combinations of bus bar configurations ona single EC coating, almost endless variations in the gradients arepossible.

Low Leakage Current Requirements

The EC device tinting or clearing operation can be divided into a drivestep and hold step, e.g. where there is a ramp in voltage followed by aconstant voltage, respectively. For monolithic EC device coatingswithout physical breaks/scribes/resistance zones, but having tint zonesas described herein, it is especially important that the leakage currentof the device is as low as possible. This is because, the leakagecurrent can normalize or diffuse out any gradients setup due toconduction over the TCOs and change in the V_applied. Thus, leakagecurrents <5 μA/cm² are desirable to ‘freeze’ the gradients setup in thewindow. Such low leakage current EC coatings are described, e.g., in USPatent.

Advantages of no break in EC stack; Smooth gradients vs. Sharptransition

With respect to user aesthetics for gradient tinting EC windows, it ispreferable not to have any sharp transitions in Tvis, but rather agradual shading from one end to the other.

In certain embodiments, an EC lite may be configured to have acombination of tint gradient zones and tint zones that do not have tintgradient capability (non-gradient tint zones). One embodiment is amonolithic EC device having two or more tinting zones, where at leastone tinting zone is a tint gradient zone and at least one tinting zoneis a non-gradient tint zone. One embodiment is a monolithic EC devicehaving two or more tint gradient zones, with or without also having anon-gradient tint zone.

In one embodiment, the bus bars described in relation to FIG. 4F areconfigured such that each highly electrically conductive portion, 460 a,460 b, and 460 c, has its own electrical connection to a power source.Analogous to the separate bus bar pairs described in relation to FIG. 4A(or FIG. 3A or 3D), the bus bars described in relation to FIG. 4F, whenconfigured with each highly electrically conductive portion 460 havingits own power source (or sources, e.g. as described in relation to FIG.4H), may be used to create tint gradient zones with tinting patternssimilar to those described in relation to FIGS. 4B and 4C.

In certain embodiments that use powering mechanisms alone to createtinting zones, the tinting front may not be a clean line, but ratherhave a diffuse appearance along the tinting front due to the chargebleeding off into the EC device's adjacent zone which is not powered atthe time. In certain embodiments, resistive zones may be used to aid inmaintaining more well-defined tinting fronts. Resistive zones aredescribed in more detail below.

Resistive Zones with or without Configuring Powering Mechanism of ECDevices

In certain embodiments, resistive zones are configured in the monolithicEC device. These resistive zones may allow for more uniform tintingfronts, e.g., when used in combination with bus bar powering mechanismsdescribed herein. Referring to FIG. 5A, an EC lite, 500, much like EClite 200 of FIG. 2A, is configured with two pairs of bus bars forcreating two tinting zones, in this example (as depicted) a top and abottom zone. EC lite 500 may be incorporated into an IGU, 510, with aspacer 110 and a mate lite 115 as depicted. A major difference betweenlite 200 of FIG. 2A and lite 500 of FIG. 5A is that lite 500 does nothave a laser scribe 225 across the lite to bifurcate the EC device intotwo devices. Lite 500 has a single EC device over the viewable area ofthe lite. However, the EC device on lite 500 includes a resistive zone,505, that spans the width of the EC device. The heavy dotted line inFIG. 5A indicates the approximate position of resistive zone 505.

As depicted in the IGU construct 510, resistive zone 505, like laserscribe 225, may not be visible to the naked eye when the EC lite's zonesare not tinted. However, unlike laser scribe 225, when adjacent tintingzones of EC lite are tinted, resistive zone 505 may not be visuallydiscernible to the naked eye. This is illustrated schematically in theright portion of FIG. 5B. The reason resistive zone 505 tints is becauseit is not a physical bifurcation of the EC device into two devices, butrather a physical modification of the single EC device coating and/orits associated transparent conductors within a resistive zone. Theresistive zone is an area of the EC device where the activity of thedevice is impeded, specifically through higher electrical resistivityand/or greater resistance to ion movement and/or lower ion densitycompared to the remainder of the EC device. Thus one or both of thetransparent conductors may be modified to have increased electricalresistivity in the resistive zone, and/or the EC device stack may bemodified so that ion movement is slower in the resistive zone relativeto the EC device stack in the adjacent tinting zones. The modificationsmay be made during deposition of the EC device or post depositionthrough a thermal and/or laser treatment. The EC device still functions,tints and bleaches, in this resistive zone, but at a slower rate and/orwith less intensity of tint than the remaining portions of the ECdevice. For example, the resistive zone may tint as fully as theremainder of EC device in the adjacent tinting zones, but the resistivezone tints more slowly than the adjacent tinting zones. In anotherexample, the resistive zone may tint less fully than the adjacenttinting zones, and at a slower rate.

FIG. 5C is a perspective and a cross section, X-X, of EC lite 500 asdescribed with respect to FIGS. 5A and 5B. The cross section, X-X, spansthe upper and lower tinting zones (tinting zones 1 and 2, respectively)of EC lite 500 as well as resistive zone 505 (only the bus bars on thetop TCO are depicted in cross section X-X, they are orthogonal toresistive zone 505 in this example). Cross section X-X (lower portion ofFIG. 5C) is not to scale, but rather a schematic representation of thestructure of EC lite 500. On the glass substrate is an EC deviceincluding a first transparent conducting oxide layer, TCO 1, a secondtransparent conductive oxide layer, TCO 2, and sandwiched in between theTCOs is an EC stack which contains one or more electrochromic materials,e.g., the transitions of which are driven byintercalation/de-intercalation of ions, such as lithium ions. Resistivezone 505 is an area in the EC device where one or more layers of the ECdevice have their function impaired, either partially or completely, butdevice function is not cut off across the zone. For example, one or bothof the TCOs has a higher resistance to electrical flow in resistive zone505 than in the tinting zones. Thus, e.g., if tinting zone 1 isactivated, electrons flow across the TCOs at a given rate, but that flowis restricted along resistive zone 505. This allows the electrons to besufficiently retained in tinting zone 1 and thus leak more slowly acrossresistive zone 505 than otherwise would be the case if TCO function hadnot been impaired there.

Resistive zone 505 could be thought of as a “dam” for electrical and/orionic flow, impairing rate of flow (either ionic current or electroniccurrent) across it, the flow can be partially or fully impaired in oneor both TCOs, for example. Due to the restricted or slowed rate ofelectrical flow across resistive zone 505, ion intercalation in the ECstack between the TCOs at resistive zone 505 is also impaired. Becausethe EC device is not physically cut into two devices, this is unlikeconventional devices having zones created by physical bifurcation of onemore layers of a single device coating. Resistive zone 505 may havephysical impairment of ion flow in one or more of the EC materiallayers. In one example, both the top and bottom TCO's electricalconductivity is impaired, either partially or fully, in resistive zone505, but the function of the EC device stack layers is substantiallyunchanged. Thus, when one tinting zone is tinted and the adjacent zoneis not-tinted, the device will tint under resistive zone 505. Whenadjacent tinting zones are both tinted, there is no bright linediscernible to the end user, because the device tints under resistivezone 505. In embodiments where ion flow is impaired in resistive zone505, the device may still color, but more slowly than the bulk device.This rate difference in coloring may or may not be visually discernibleto the end user.

Resistive zone 505 may be fabricated, for example, by exposure of thearea at the resistive zone 505 to irradiation, e.g. laser or heatsource, in order to modify but not destroy the function at resistivezone 505. For example, one or both of the TCO layers may be heatedsufficiently to change the morphology while retaining the function,albeit impaired relative to the remainder of the TCO layers in thetinting zones. In certain embodiments, it is advantageous to impair thefunction of only one TCO in a resistive zone. Resistive zones may alsobe created by impairing the function of one or more layers of the ECdevice (including, or not, one or both TCOs) by chemical doping. Forexample, in one embodiment the lower TCO is treated along a line (atresistive zone 505, e.g.) with heat and oxygen to create a moreresistive TCO at the resistive zone. In another embodiment, one or bothTCOs are fabricated thinner along the resistive zone than the rest ofthe TCOs, e.g. TCO material may be removed, but not cut through, alongthe resistive zone. In another example heating along the zone maydensify the EC materials while having no effect on the TCO layers; ormay affect the TCO layers as well.

In certain embodiments, the resistive zones may be narrow, e.g. betweenabout 1 μm and 1000 μm wide, or may be wider, e.g. between about 1 mmand about 10 mm wide. Because the EC materials in resistive zones tintand do not necessarily leave a bright line contrast effect typical ofconventional laser isolation scribes, there is less concern as to thewidth of the described resistive zones. Thus, in other embodiments, aresistive zone may be, for example, wider than 1 mm, wider than 10 mm,wider than 15 mm, etc.

In the embodiment described in relation to FIGS. 5A, 5B, and 5C, each ofthe tinting zones has its own unique pair of bus bars. Thus tintingzones can be colored independently by virtue of operation or therespective bus bar pairs at each tinting zone. In other embodiments,multiple tinting zones may be configured to share a common bus bar,while still being independently controllable.

FIG. 5D depicts a perspective (top portion) and a cross section Y-Y(bottom portion) of an EC lite, 510, having two tinting zones ofvariable tinting level by virtue of a resistive zone, 515. In thisillustrated example, a single set of three bus bars, 525(a), 525(b), and520, is used with two tinting zones. Cross section, Y-Y, of EC lite 510spans left and right tinting zones (tinting zones 1 and 2, respectively)of lite 510 as well as resistive zone 515. Resistive zone 515 runsparallel to and between (approximately in the middle of EC lite 510) busbars 520 and 525(a) and bus bar 525(b) (from top to bottom as depictedin the perspective at the top of FIG. 5D). Cross section Y-Y (lowerportion of FIG. 5D) is not to scale, but rather is a schematicrepresentation of the structure of EC lite 510. On the glass substrateis an EC device including a first transparent conducting oxide layer,TCO 1, a second transparent conductive oxide layer, TCO 2, andsandwiched in between TCO 1 and TCO 2 is an EC stack which contains oneor more electrochromic materials, e.g., the transitions of which aredriven by intercalation/de-intercalation of ions, such as lithium ions.In this example, resistive zone 515 is an area of TCO 2, where the TCOfunction is impaired but not eliminated. For example, TCO 2 may have itsfunction impaired along a line.

FIG. 5E includes two graphs showing plots of the local voltage V_(TCL)in TCO 1 and TCO 2 of the EC lite, 510, of FIG. 5D that drivestransition. At the left, a graph shows a curve 526 of the local valuesof V_(TCL) in the TCO 1. At the right, a graph shows a curve 528 of thelocal values of V_(TCL) in the TCO 2. In this example, when the ECdevice is energized, the bottom TCO 1 has a local voltage potentialV_(TCL) across its span similar to that of a typical transparentconductor for an EC device. According to curve 526 of V_(TCL) in TCO 1,the voltage increases slightly in the middle away from where bus bars525(a) and 525(b) are disposed on TCO 1 where voltage is applied due tothe sheet resistance and current passing through TCO 1. The increasewill be near bus bar 525(a) and bus bar 520 because of the highercurrent in this area due to higher voltage potential between bus bar525(a) and bus bar 520. But TCO 2, by virtue of resistive zone 515, hasa higher V_(TCL) in tinting zone 1 than in tinting zone 2. According tocurve 528 V_(TCL) in TCO 2, the slight voltage drops between the lefthand side where bus bar 520 is disposed on TCO 2 and the resistive zonedue to sheet resistance and current passing through TCO 2. At theresistive zone 515, the voltage sharply drops. The voltage slightlydrops between the resistive zone 515 and the right hand side due tosheet resistance and current passing through TCO 2. The value of V_(eff)at any location between the bus bars is the difference in values ofcurves 130 and 125 at that position on the x-axis corresponding to thelocation of interest. The result is that tinting zone 1 has a higherV_(eff) than tinting zone 2 and thus tinting zone 1 colors more darklythan tinting zone 2. This is represented in FIG. 5F. On the left of FIG.5F, a visible coloration difference is seen in window 510 correspondingto the location of resistive zone 515 and the rather abrupt drop involtage in TCO 2 as reflected in FIG. 5E. However, this visualcoloration difference need not be so; that is, for example, if resistivezone 515 is sufficiently “leaky”, and allows voltage to flow across thetop TCO in a smooth gradient (or if window 510 is configured withoutresistive zone 515 and the voltage applied to TCO 2 is insufficient toovercome a voltage drop across TCO 2) then a gradual transition fromdarker to lighter results (see FIG. 4F, right side) due to the voltagedrop over. Of course, the two tinting zones can be configured as upperand lower portions when installed in a building, and they need not beside by side as depicted.

FIG. 5G depicts an EC lite, 530, configured with a resistive zonecreated by inhibiting the electrical conductivity of only one of thetransparent conducting oxides. The EC lite is much like the onedescribed in relation to FIG. 5E, but in this embodiment one of the TCOsis cut through along the resistive zone (cut 550), while the other TCOis left intact. The EC device stack is unchanged in the resistive zone,only the top TCO is cut. The EC lite 530 has two sets of bus bars, 535and 540. Bus bar set 535 powers the lower TCO 1, while bus bar set 540powers the top TCO 2. The lower portion of FIG. 5G shows cross sectionZ-Z. The EC device will still at least partially color along theresistive zone by virtue of one of the TCOs being fully intact,monolithic, along with the EC stack. While there is a narrow region ofthe opposite TCO 2 missing, there is sufficient voltage potentialestablished between the intact TCO 1 and the edge of the cut (opposing)TCO 2 along the resistive zone to allow coloration of the EC device inthe resistive zone, albeit more slowly than if both TCOs were intactalong the resistive zone. The resistive zone may color more lightly whenonly one of the tinting zones is powered, while with both tinting zonespowered, the resistive zone may fully tint or approximate full tinting.Each portion of TCO 2 can be powered independently of TCO 1. In thisway, separate zones, tinting zone 1 and tinting zone 2, may, e.g., betinted more effectively. Since there is a cut through the TCO 2, if onlyone zone is powered, a tinting level of V_(TCL) is only established inthat tinting zone. The cut in TCO 2 aids in establishing and maintaininga uniform tinting front. In this example, since the TCOs are a type ofmoisture barrier, EC lite 530 may be incorporated into an IGU where theEC device is hermetically sealed within the volume of the IGU, and/or atop coat may be used to hermetically seal the device, with our withoutlamination to a substrate. A top coat would fill the open trench cutthrough TCO 2.

In certain embodiments, it may be more desirable to cut the bottom TCO 1rather than the top TCO 2. FIG. 5H shows EC lite, 530 a, where the cut,550 a, is made only through the bottom TCO 1. In this example, the topTCO 2 may maintain its hermeticity by virtue of an intact toptransparent conductor layer. The EC material may fill in the trench madeby cut 550 a, and thus tint along with the trench in TCO 1 that itfills, providing an area of inhibited coloration rate such as aresistive zone.

In certain embodiments, it may more desirable to cut the top TCO 2rather than the bottom TCO 1. FIG. 5G shows EC lite, 530, where the cut,550, is made only through the top TCO 2. An advantage of this embodimentmay be that the cut can be made after the EC device is fabricated, forexample, by laser processing performed after sputter coating.

The bus bars 535 and 540 depicted in FIGS. 5G and 5H need not beparallel, e.g. the bus bars powering each TCO can be orthogonal to eachother. Also, the single monolithic TCO need not have two bus bars, butit is desirable so as to have more control over tinting of theindividual tinting zones. Bleaching function would work the same way butin reverse polarity to bleach the tinting zones. In the embodimentsdescribed in relation to FIGS. 5D-5H, the bus bars are configuredparallel to the resistive zone; in FIGS. 51 and 5J, like in FIG. 5C,e.g., the bus bars are configured orthogonally to the resistive zone.

In certain embodiments, there are no bus bars in the viewable area ofthe EC device, that is, in the area within the spacer of the IGU.Certain conventional EC technologies rely on bus bars running throughthe viewable area because of slow switching kinetics that wouldotherwise occur and/or due to ion conductor layer leakage currents thatdo not allow the EC device to switch across the entire viewable area oflarger IGUs (e.g. about a meter wide or more where bus bars wouldotherwise be configured outside the viewable area at the edges of thiswidth) without such bus bars in the viewable area to provide the extravoltage needed to compensate for the leakage current. Certainembodiments described herein, e.g. where cuts are made through one ofthe TCOs but not the EC device stack itself, do not require bus bars inthe viewable area because they include EC devices with very low leakagecurrent. Examples of such devices are described in U.S. patentapplication Ser. No. 12/814,279, filed Jun. 11, 2010, which is hereinincorporated by reference in its entirety. For example, the embodimentsdescribed where the resistive zone includes a cut through one of theTCOs include examples where there are no bus bars in the viewable areaof the EC device.

FIG. 5I depicts an EC lite, 555, configured with a resistive zone, 570,created by inhibiting the electrical conductivity across one of thetransparent conducting oxides, in this example a cut is made through theTCO nearer the substrate. The EC lite is much like the one described inrelation to FIG. 5C, but in this embodiment one of the TCOs is cutthrough along the resistive zone (cut 570), while the other TCO is leftintact. The EC device stack is unchanged in the resistive zone area,only the bottom TCO is cut. The EC lite 555 has two sets of bus bars,560 and 565. Bus bar set 560 powers both the upper and the lower TCOs intint zone 1 (TCO 1 and TCO 2), while bus bar set 565 powers tint zone 2.The lower portion of FIG. 5I shows cross section V-V (only the bus barson TCO 2 are depicted). The EC device will still at least partiallycolor along the resistive zone by virtue of one of the TCOs being fullyintact, monolithic, along with the EC stack. While there is a narrowregion of the opposite TCO 1 missing, there is sufficient voltagepotential established between the intact TCO 2 and the edge of the cut(opposing) TCO 1 along the resistive zone to allow coloration of the ECdevice in the resistive zone, albeit more slowly than if both TCOs wereintact along the resistive zone. The resistive zone may color morelightly when only one of the tinting zones is powered, while with bothtinting zones powered, the resistive zone may fully tint or approximatefull tint. Each portion of TCO 1 can be powered independently of TCO 2.In this way, separate zones, tinting zone 1 and tinting zone 2, may,e.g., be tinted more effectively. Since there is a cut through the TCO1, if only one zone is powered, a tinting level V_(TCL) is onlyestablished in that tinting zone. The cut in TCO 1 aids in establishingand maintaining a uniform tinting front. In this example, since the TCOsare a type of moisture barrier, EC lite 555 may be incorporated into anIGU where the EC device is hermetically sealed within the volume of theIGU, and a top coat may not be necessary because TCO 2 remains intact,although in one embodiment a top coat is applied to TCO 2. Because thebus bars in EC lite 555 are orthogonal to the resistive zone 570, thetinting front is also orthogonal to the bus bars.

FIG. 5J depicts an EC lite, 555 a, configured with a resistive zone, 570a, created by inhibiting the electrical conductivity across one of thetransparent conducting oxides, in this example a cut is made through theTCO distal the substrate. The EC lite is much like the one described inrelation to FIG. 5I, but in this embodiment TCO 2 is cut through whileTCO 1 is left intact. The EC device stack is unchanged in the resistivezone area, only the top TCO is cut. The EC lite 555 a has two sets ofbus bars, 560 and 565. Bus bar set 560 powers both the upper and thelower TCOs in tint zone 1 (TCO 1 and TCO 2), while bus bar set 565powers tint zone 2. The lower portion of FIG. 5J shows cross section T-T(only the bus bars on TCO 2 are depicted). The EC device will still atleast partially color along the resistive zone by virtue of one of theTCOs being fully intact, monolithic, along with the EC stack. Whilethere is a narrow region of the opposite TCO 2 missing, there issufficient voltage potential established between the intact TCO 1 andthe edge of the cut (opposing) TCO 2 along the resistive zone to allowcoloration of the EC device in the resistive zone, albeit more slowlythan if both TCOs were intact along the resistive zone. The resistivezone may color more lightly when only one of the tinting zones ispowered, while with both tinting zones powered, the resistive zone mayfully tint or approximate full tinting. Each portion of TCO 2 can bepowered independently of TCO 1. In this way, separate zones, tintingzone 1 and tinting zone 2, may, e.g., be tinted more effectively. Sincethere is a cut through the TCO 2, if only one zone is powered, a tintinglevel of V_(TCL) is only established in that tinting zone. The cut inTCO 2 aids in establishing and maintaining a uniform tinting front. Inthis example, since the TCOs are a type of moisture barrier, EC lite 555a may be incorporated into an IGU where the EC device is hermeticallysealed within the volume of the IGU, and a top coat may be necessarybecause TCO 2 is cut through, in one embodiment a top coat is applied toTCO 2. Because the bus bars in EC lite 555 a are orthogonal to theresistive zone 570 a, the tinting front is also orthogonal to the busbars.

When two bus bars ends of opposite polarity are located proximate eachother on an intact TCO, hot spots can result. Hot spots are described inU.S. patent application Ser. No. 13/452,032, filed Apr. 20, 2012 whichis incorporated by reference herein in its entirety. When using TCOsthat are cut through, e.g. as depicted in FIG. 5J, hot spots may beavoided because the proximate bus bars of a TCO layer cannotelectrically communicate with each other through the TCO. However, toavoid stress on the underlying EC device in the area along the resistivezone formed by cutting through TCO, the ends of the bus bars may beconfigured so they are not directly over (aligned with) the cut made forthe resistive zone.

One embodiment is an EC lite as described herein, where a resistive zoneis formed by partially cutting through one or both of the TCOs. Forexample, in one embodiment, e.g. analogous the embodiment described inrelation to FIG. 5J, the top TCO is only cut part way through, ratherthan cut through. In this way a resistive zone is established and thehermiticity of the EC device, imparted by the top TCO is left at leastpartially intact. FIG. 5K depicts another example.

FIG. 5K depicts an EC lite, 575, configured with two resistive zones,580 a and 580 b, created by inhibiting the electrical conductivityacross one of the transparent conducting oxides. In this example,partial cuts are made through the TCO distal the substrate (TCO 2). TheEC lite is much like the one described in relation to FIG. 5J, but inthis embodiment TCO 2 is not cut through, but only some TCO material isremoved to form resistive zones 580 a and 580 b. For example, laserablation is used to remove material only down to a fraction of the depthof the ITO. In one embodiment, between about 10% and about 90% of theTCO material is removed along the zone, in another embodiment betweenabout 25% and about 75% of the TCO material is removed, in yet anotherembodiment between about 40% and about 60% of the material is removed.By removing only part of the TCO material, a resistive zone isfabricated while not exposing the EC stack to the ambient. Lite 575 hasthree tint zones, by virtue of having two resistive zones. The EC lite575 has three sets of bus bars, 560, 565 and 566. Bus bar set 560 powersboth the upper and the lower TCOs in tint zone 1 (TCO 1 and TCO 2), busbar set 565 powers tint zone 2, and bus bar set 566 powers tint zone 3.Each tint zone can be independently controlled via powering the bottomTCO, and independently charging the TCO 2 bus bars, depending upon whichzone tinting is desired. Because the resistive zones have a higher sheetresistance relative to the bulk TCO, charge loss over this barrier isslow and allows the powered zone to fully tint while the tinting frontapproximates the position of the resistive zone.

The lower portion of FIG. 5K shows cross section S-S (only the bus barson TCO 2 are depicted). The EC device will still at least partiallycolor along the resistive zone by virtue of TCO 2 being fully intact,monolithic, along with the EC stack. The resistive zone may color morelightly when only one of the tinting zones is powered, or not at all,depending on its width and the thickness of the TCO in the resistivezone. With adjacent tinting zones powered, the resistive zone may fullytint or approximate full tinting. In this example, since the TCOs are atype of moisture barrier, EC lite 575 may be incorporated into an IGUwhere the EC device is hermetically sealed within the volume of the IGU,and a top coat may be necessary because TCO 2 is at least partially cutthrough, in one embodiment a top coat is applied to TCO 2. Because thebus bars in EC lite 575 are orthogonal to the resistive zones 580 a and580 b, the tinting front is also orthogonal to the bus bars andapproximates the line defined by the resistive zones.

Note, in FIG. 5K, the bus bars ends are substantially coextant with theresistive zones. In one embodiment, bus bar material is applied and thenthe resistive zones are formed by cutting through the bus bar materialand at least some of the top TCO. In certain embodiments the top TCO iscut through, while not cutting the EC device stack through (a portion ofthe EC stack may be cut, but sometimes not through the IC material so asnot to form electrical shorts along the resistive zone). By applying,e.g., only two lines of bus bar material (e.g. silver based ink) andfiring the bus bars, the resistive zones and individual bus bar pairscan be fabricated in the same process by cutting through the bus barmaterial and into or through the top TCO simultaneously. This savesprocess steps. The bus bar on the bottom TCO 1 is cut through withoutcutting through the bottom TCO. In one embodiment the bus bars on thetop TCO are formed by cutting through along with the top TCO, eitherfully or partially cut, while the bottom bus bars are applied separatelyto each tinting zone. In certain embodiments, each tinting zone's busbars are applied individually to each tinting zone. The latter may bedone to avoid the aforementioned hot spots, e.g. when cutting throughthe bus bar and TCO in the same process, the ends of the newly formedbus bars are necessarily aligned with the cut in the TCO, since theywere from the same cutting process.

Resistive Layer Through EC Stack Changes to Speed/Coloration Efficiency

In certain embodiments, a resistive zone can be created by changing theelectrochromic behavior of one or more layers of the EC stack vs.applied voltage. In this case, the resistive zone provides a resistanceto coloration rather than electrical resistance per se. For example, theresistive zone may color slowly or less deeply (higher Tvis) compared tothe rest of the device at same V_(eff). This can be achieved by, forexample, 1) reducing the dose of ions (typically Li⁺) causing theelectrochromic reaction, 2) changing the properties of theelectrochromic layers (EC, CE) such that the optical change per ion isreduced (i.e. reduced coloration efficiency), 3) reducing ion mobilityin the EC and/or CE layers in the resistive zone, and/or 4) increasingthe thickness of the IC layer and/or reducing ion mobility in the IClayer such that it is harder for the ions to move across the IC layer.Any of these changes can be done during deposition and/or postfabrication. For example, local heating of the EC stack duethermal/laser irradiation can be used, or for example, selectivelyaltering deposition rate and/or oxidation state in the resistive zonerelative to the bulk device.

Certain embodiments concern methods of fabricating apparatus and devicesdescribed herein. One embodiment is a method of forming an EC litehaving two or more tinting zones, the method including a) forming a ECdevice (e.g., a monolithic EC device), b) applying a single bus bar tothe top TCO of the monolithic EC device, and c) cutting through the busbar and at least part way through the top TCO thereby fabricating saidtwo or more tinting zones each having separate bus bars on the top TCOby virtue of c.

Resistive zones need not be linear as depicted, but rather may be of anyshape. For example, for desired effects, one might choose a resistivezone that is zigzagged, curved or irregularly shaped along adjacenttinting zones.

In certain embodiments, resistive zones are used to define a perimeter,closed or open, of a region of an EC window, that is, a sub-portion(area) of a monolithic EC device. For example, these resistive zones canbe used to highlight particular symbols or shapes in the viewable regionof the EC window. One embodiment with such a resistive zone isillustrated in FIGS. 6A and 6B. For example, an end user may wish tohave an area of the EC window that does not tint, or that becomes tintedmore slowly, than the remainder of the tintable EC window.

FIG. 6A depicts an EC lite, 600, which includes a single pair of busbars, 105, as well as a resistive zone, 605. In this example, theresistive zone is in the shape of a closed rectangle (as indicated bythe dotted line). Resistive zone 605 may not be visually discernible tothe naked eye. In one embodiment, resistive zone 605 is configured suchthat the portions of the TCOs of the EC device in the resistive zone (asindicated by the dotted line) have a higher electrical resistance thanthe portions of the TCOs in the remainder of the EC device on eitherside of the resistive zone (in this example both outside and inside therectangular perimeter zone), but the resistive zone still passes charge.In this embodiment, when the EC device is tinted, the area around theresistive zone 605 tints first, the tinting front slowing when itreaches the rectangular closed resistive zone 605. This momentarily,e.g. for a period of minutes, gives the effect of a small untinted viewport in a larger tinted window. As the charge bleeds beyond theresistive zone and into the untinted rectangular region within the zone,this gives the effect of the small untinted view port closing as ittints. In another embodiment, resistive zone 605 is configured such thatthe portions of the TCOs of the EC device in the resistive zone (asindicated by the dotted line) have a very high resistance to electricalcharge as compared to the portions of the TCOs in the remainder of theEC device on either side of the resistive zone (in this example bothoutside and inside the rectangular perimeter zone), that is, theresistive zone effectively blocks electrical charge. In this embodiment,when the area outside the zone is tinted, the area inside the zone maynever tint because the charge may not be able to pass the resistivebarrier 605. This gives the effect of a small untinted view port in alarger tinted window, so long as the EC device is tinted. In anotherembodiment, resistive zone 605 is configured such that the portions ofthe TCOs of the EC device in the resistive zone (as indicated by thedotted line) and in the region within the resistive zone have a veryhigh resistance to electrical charge as compared to the portions of theTCOs in the remainder of the EC device on the outside of the resistivezone.

FIG. 6B shows a similar EC lite, 610, having a resistive zone, 615,which is “open” by virtue of a gap, 620, in the perimeter. In thisexample, the resistive zone 615 is configured to block electricalcharge. When the EC device is tinted, the area around the resistive zone615 tints first, the tinting front slowing when it reaches therectangular closed resistive zone 615, except at the open portion 620,where the tinting front gives the effect of “pouring in” or “filling in”(as indicated by the two dotted arrows) the rectangular region withinresistive zone 615. Eventually, when the area inside resistive zone 615is tinted, resistive zone 615 may no longer be discernible to the nakedeye, as the EC device colors under the zone, as described above.Configuring resistive zones in such a way can be used to achievepermanent or transient tinting effects on EC windows, e.g., to display alogo or words in a transient manner for presentation during marketingpurposes, or to achieve tinted and non-tinting zones on an EC lite. EClites so configured can be incorporated into IGUs as describe and/orlaminated with mate lites.

Multi-EC Lite Patterns

Embodiments described can also be used to create patterns that encompassmore than one IGU, laminate or other construct containing one or moremonolithic EC lites. For example, as depicted in FIG. 7, an EC lite,700, is configured with a resistive zone or zones, such that a portion,710, of the EC lite does not color, or colors less intensely than thebulk device (the dotted lines are only to depict where the portion 710is on the EC lite). Four similarly configured lites 700 are arranged sothat when colored, they form a display, such as the letter “O” in thisexample.

Many such lites can be configured for display purposes, e.g. on acurtain wall or façade of a building for advertising purposes. Since ECmonolithic EC lites can be made quite large, e.g., 6 feet×10 feet, verylarge words, symbols, ornamental designs and the like can be made forretail facades, schools, military installations, airports and the like.Moreover, since e.g. laminates and/or IGUs can have two or moreregistered EC lites, and each EC lite of any laminate and/or IGU canhave tinting features as described herein, many possibilities forchanging words, symbols and/or ornamental designs are possible. Forexample, as depicted in FIG. 8, a glass facade, 800, has eight 5′×10′triple pane IGUs, each IGU having three EC lites, each EC lite ispatterned with resistive zones such that different words can bedisplayed on the facade. In this example, the letters of the words areapproximately 6′ high, however any pattern, size or arrangement ispossible. In one embodiment, the facade includes a “normal” mode whereno words are displayed, rather the glass is tinted uniformly across alleight IGUs. The multi-EC lite pattern can be used for skylights,facades, or any place where such displays are desired, e.g. in largeskylights at airports or other buildings, words and/or symbols, changingor not, can be communicated to aircraft.

Gradient zoning can also be done across multiple EC lites, e.g.laminates and/or IGUs, for example as depicted in FIG. 9. FIG. 9 depictsa glass facade, 900, having eight 5′×10′ IGUs. In this example, each IGUhas a single EC lite, each configured with a monolithic EC devicecoating and appropriate bus bars and electrical control (e.g. dual feedbus bars as described above) so that each IGU can fully bleach, fullytint, or create gradient coloration across the entire monolithic ECcoating. Referring again to FIG. 9, the facade can be made to tint in agradient from dark to light, from top to bottom, respectively (topfaçade), tint uniformly across all IGUs (middle façade) or e.g. tint ina gradient from dark to light, from bottom to top, respectively.

One of ordinary skill in the art, armed with this disclosure, wouldappreciate that tint gradient zones can be used with resistive zones andthis combination is within the scope of the embodiments describedherein. For example a single EC lite, or a façade, can be made to bothtint with gradients and display words, symbols and the like.

Although the foregoing embodiments have been described in some detail tofacilitate understanding, the described embodiments are to be consideredillustrative and not limiting. It will be apparent to one of ordinaryskill in the art that certain changes and modifications can be practicedwithin the scope of the above description and the appended claims.

We claim:
 1. An electrochromic window lite comprising: (i) a monolithicelectrochromic device on a transparent substrate, the monolithic ECdevice comprising two transparent conductive oxide (TCO) layers; and(ii) two or more tinting zones, each of said two or more tinting zonesconfigured for operation independent of the others; and (iii) aresistive zone between each of said two or more tinting zones, theresistive zone being a partial cut through the uppermost TCO layer ofthe two TCO layers.
 2. The electrochromic window lite of claim 1,wherein each of said two or more tinting zones comprises its ownassociated bus bars located at opposing edges for each of the two ormore tinting zones.
 3. The electrochromic window lite of claim 1,wherein the electrochromic window lite is incorporated into an insulatedglass unit (IGU).
 4. The electrochromic window lite of claim 3, whereinthe IGU has a mate lite that is not an electrochromic lite.
 5. Theelectrochromic window lite of claim 3, wherein the IGU has a mate litethat is a monolithic electrochromic lite with a single tinting zone. 6.The electrochromic window lite of claim 3, wherein the IGU has a matelite that is a monolithic electrochromic lite with two or more tintingzones.
 7. The electrochromic window lite of claim 6, configured to tintin any one or more tinting zones to <1% T.
 8. The electrochromic windowlite of claim 1, wherein the resistive zone substantially spans acrossthe width of the monolithic electrochromic device.
 9. The electrochromicwindow lite of claim 1, wherein the resistive zone is between about 1 nmwide and about 10 nm wide.
 10. The electrochromic window lite of claim9, wherein the resistive zone is formed by removing between about 10%and about 90% of the uppermost TCO layer along the resistive zone. 11.The electrochromic window lite of claim 10, wherein the resistive zoneis formed by laser irradiation of the uppermost TCO layer.
 12. Theelectrochromic window lite of claim 2, wherein each of said two or moretinting zones associated bus bars are formed by laser irradiation duringformation of the resistive zone by cutting through a single bus bar. 13.A method of forming a monolithic electrochromic (EC) device comprisingtwo tinting zones, the method comprising: a) forming the monolithic ECdevice comprising two transparent conductive oxide (TCO) layers; b)applying a single bus bar to the uppermost TCO layer of the two TCOlayers of the monolithic EC device; c) cutting through the single busbar along its width; and d) cutting at least part way through theuppermost TCO layer, but not entirely through the uppermost TCO and notthrough an electrode material layer adjacent to the uppermost TCO layer,to form a resistive zone between the two tinting zones; wherein c) formsseparate bus bars for each of the two tinting zones from the single busbar.
 14. The method of claim 13, wherein c) and d) are performed in asingle cutting step.
 15. The method of claim 13, wherein the resistivezone substantially spans the width of the monolithic EC device.
 16. Themethod of claim 13, wherein the resistive zone is between about 1 nmwide and about 10 nm wide.
 17. The method of claim 13, wherein theresistive zone is formed by removing between about 10% and about 90% ofthe uppermost TCO layer along the resistive zone.
 18. The method ofclaim 17, wherein the resistive zone is formed by laser irradiation ofthe uppermost TCO layer.
 19. An electrochromic window lite comprising: atransparent substrate having a viewable area; an electrochromic devicedisposed on the viewable area of the transparent substrate; a region ofthe viewable area that is not covered by the electrochromic device, saidregion capable of providing a bright spot or bright region when theelectrochromic device is tinted; and an obscuring material over theregion of the viewable area that is not covered by the electrochromicdevice, wherein the obscuring material has a lower transmittance thanthe transparent substrate.
 20. The electrochromic window lite of claim19, wherein the region of the viewable area that is not covered by theelectrochromic device is a pinhole, a scribe line, or an edge line. 21.A method of obscuring a potentially bright area produced by a region ofa viewable area of a transparent substrate that is not covered by anelectrochromic device, the method comprising: i. providing anelectrochromic lite having the electrochromic device disposed on theviewable area of the transparent substrate; ii. identifying a site ofthe region on the viewable area that is not covered by theelectrochromic device; and iii. applying an obscuring material to theregion of the viewable area that is not covered by the electrochromicdevice; wherein the obscuring material has a lower transmittance thanthe transparent substrate.
 22. The method of claim 21, wherein theregion of the viewable area that is not covered by the electrochromicdevice is a pinhole, a scribe line, or an edge line.